PDA

View Full Version : Mystery blob on Tmax 400 sheet



rdeloe
14-Feb-2019, 14:18
I developed some TMax 400 in my Spearman SP 445. I used Xtol 1+1 (8.75 minutes), stop with water, and fix for 6 minutes with Ilford Rapid Fixer.

One sheet came out of the tank with this strange blob in the corner (looks like it's on the emulsion side). The other sheet that was developed at the same time is fine. Neither has purple/magenta staining (which usually points to inadequate fixing) anywhere else. The fixer was not fresh, but is far from exhausted. The developer was mixed from fresh stock.

In this picture I'm showing you just the corner of the sheet where the blog is located.

187738

The film has not been frozen (by me anyway), it's the first sheet out of a new package, and the package was bone dry (so there was no moisture on the film). It loaded easily into the film holder, and easily into the SP 445 holder after it was exposed; the SP 445 holder was also bone dry. Finally, it was positioned properly in the holder during development (as far as I can tell); when I opened the tank it was still in the holder.

Any ideas as to what this might be?

Note: the rough lines you can see at the edge of the film are actually guide lines scored into the underside of the glass that I use for camera scanning (so they're not on the film and have nothing to do with this problem).

Doremus Scudder
14-Feb-2019, 15:05
It looks like the sheet was in contact with part of the tank at that spot during processing. If you're lucky, it's just residual anti-halation dye on the back of the film. Try washing in water in a tray. If that doesn't work, refix and see if that helps. If the contact was on the emulsion side, refixing will take all the undeveloped halides away, leaving a clear spot.

Good luck,

Doremus

rdeloe
14-Feb-2019, 18:06
Thanks Doremus. That was my thought too. One time I did have one sheet touching another sheet (mis-loaded), and that pattern resulted over a large area of the negative, so it makes sense. But in this case I was careful to load the sheets on the correct sides of the holder, and they were still in the holder (not touching the tank) when I was done. Very strange.

Steven Ruttenberg
14-Feb-2019, 20:46
Maybe a light leak. You can see the banding moving out from blob.

koraks
15-Feb-2019, 00:09
Maybe a light leak. You can see the banding moving out from blob.

That wouldn't explain the remnants of antihalation dye around the spot. I agree with Doremus - the sheet was partially stuck to something else during at least a part of the process.

Leszek Vogt
15-Feb-2019, 01:17
From my 35mm experience I'd agree with Doremus....looks like the film touched something.

Les

rdeloe
15-Feb-2019, 05:49
I've had a previous "touching" problem and it definitely looks the same. The mystery is what it could have been touching. The only explanation that makes sense is that the film was the wrong way in the developing tank's holder (emulsion side in instead of out). I was careful and thought i had it correct, but I don't know what else it could have been.

Thanks all.

Peter Collins
15-Feb-2019, 07:50
I use a SP-445, too. It requires "slow and steady ahead" when loading. I've made my share of mistakes; none of them could be blamed on the tank. But, I use the tank--my only low-cost option. Since the only dark place in the condo is a small closet, I load the tank there. I am delighted each time I can close the tank and turn on the light. The rest of the process can be done at the kitchen sink.

rdeloe
15-Feb-2019, 08:44
I don't doubt my mystery blob is "operator trouble"! As with all things large format, you have to be careful and double-check.

I'm in the same boat as you Peter. I ripped my darkroom out in the early 2000s so the whole film development enterprise currently has to work with a change bag. Loading and unloading the SP 445 in a change bag is a bit awkward, but it works just fine.

jp
15-Feb-2019, 09:03
The film was touching something and the chemicals could not get to that part of the film. Refix it in a tray, rinse and dry and it will be OK if the picture is important.

Steven Ruttenberg
15-Feb-2019, 11:48
I use the sp445 and have never encountered that problem, although I have had other problems now solved. If it is the antihalation layer, left over, could wash it off maybe? The other thing is, was the tank completely dry? Did the film sit in the tank for a while before adding developer, etc? In that corner with the sp445 two pieces of film cannot touch. Maybe something on the film holder?

rdeloe
15-Feb-2019, 13:10
I use the sp445 and have never encountered that problem, although I have had other problems now solved. If it is the antihalation layer, left over, could wash it off maybe? The other thing is, was the tank completely dry? Did the film sit in the tank for a while before adding developer, etc? In that corner with the sp445 two pieces of film cannot touch. Maybe something on the film holder?

I've already discovered what happens when the film holders are not completely dry! I spoiled another sheet a few weeks ago when it became glued to the holder because it had some water droplets. Now I'm very careful to dry everything off before loading.

Thankfully it's simply a test shot so nothing of value.

Steven Ruttenberg
15-Feb-2019, 19:00
That would do it. I hang them dry towel dry etc.